This present disclosure is based on and claims priority to Chinese application for invention No. 202010468500.3, filed on May 28, 2020, the disclosure of which is hereby incorporated into this disclosure by reference in its entirety.
The present disclosure relates to the field of construction machinery, in particular to a leveling control method, device and system, a motor grader and a computer storable medium.
The motor grader is an earth moving construction machine which uses a blade as a main body and cooperates with other various replaceable operation devices to carryout a soil shoveling, leveling or shaping operation. The motor grader is mainly applied to large-area leveling operations of soil such as roads, airports, farmlands, water conservancy and the like, and construction operation scenes such as slope scraping, ditching, bulldozing, soil loosening, road ice and snow clearing and the like. The motor grader is one of important equipment in national defense construction, traffic and water conservancy basic construction, and plays a great role in national economic construction.
In order to ensure construction flatness while greatly reducing the labor intensity of an operator and improving the construction efficiency, the addition of a blade automatic elevation control function to the motor grader is an effective solution.
At present, there are mainly two types of leveling control systems for the motor grader: one is a laser-based leveling control System, and the other is a GPS (Global Positioning System)-based three-dimensional leveling system. The GPS has advantages of high precision and all-weather measurement, and can accurately detect the elevation of the blade in the leveling process of the motor grader to realize a precise leveling operation of the road surface. Accordingly, GPS is typically utilized in the leveling control systems of the motor grader to detect the elevation of the blade.
In the related art, the GPS is arranged at both ends of the blade of the motor grader to acquire the elevation of the blade in real time, which is compared with a preset elevation of the earth's surface, to adjust a lifting cylinder in real time according to a difference obtained through the comparison, so as to realize the control of the elevation of the blade.
According to a first aspect of the present disclosure, there is provided a leveling control method, comprising: respectively acquiring an elevation of a current position of a blade of a motor grader, an elevation of a target position, and a movement speed of the motor grader, wherein the target position is on the ground with a certain horizontal distance from the current position along a movement direction of the motor grader; determining a movement time of the blade from the current position to the target position according to the horizontal distance and the movement speed; determining a lifting speed of a lifting cylinder according to an elevation difference between the elevation of the target position and the elevation of the current position and the movement time; and controlling the lifting cylinder to adjust the blade to move from the current position to the target position according to the lifting speed.
In some embodiments, acquiring an elevation of a target position comprises: respectively acquiring an elevation of a Global Positioning System (GPS) and a vertical distance between the GPS and the target position, wherein the GPS is fixedly arranged relative to a frame of the motor grader; and acquiring the elevation of the target position according to the elevation of the GPS and the vertical distance between the GPS and the target position.
In some embodiments, acquiring a vertical distance between the GPS and the target position comprises: acquiring a vertical distance between a distance sensor and the target position, wherein the distance sensor is fixedly arranged relative to the frame of the motor grader; acquiring a vertical distance between the GPS and the distance sensor; and acquiring the vertical distance between the GPS and the target position according to the vertical distance between the distance sensor and the target position and the vertical distance between the GPS and the distance sensor.
In some embodiments, the distance sensor is located directly above the target position, and acquiring a vertical distance between a distance sensor and the target position comprises: acquiring a detection value obtained by the distance sensor through detecting the ground; and acquiring the vertical distance between the distance sensor and the target position according to the detection value.
In some embodiments, the distance sensor is an ultrasonic sensor or a lidar sensor, and acquiring the vertical distance between the distance sensor and the target position according to the detection value comprises: determining the detection value as the vertical distance between the distance sensor and the target position in the case that the distance sensor is the ultrasonic sensor; and determining a product of the detection value and a cosine value of a laser emission angle of the lidar sensor as the vertical distance between the distance sensor and the target position in the case that the distance sensor is the lidar sensor.
In some embodiments, acquiring an elevation of a current position of a blade of a motor grader comprises: acquiring an elevation of a Global Positioning System (GPS), wherein the GPS is fixedly arranged relative to a frame of the motor grader; and acquiring the elevation of the current position of the blade of the motor grader according to the elevation of the GPS.
In some embodiments, the GPS is located directly above the blade, and acquiring the elevation of the current position of the blade of the motor grader according to the elevation of the global positioning system (GPS) comprises: determining an elevation of a projection point of the GPS on the ground according to a distance between the GPS and the projection point of the GPS on the ground and the elevation of the GPS; and determining the elevation of the current position of the blade according to the elevation of the projection point of the GPS on the ground and a shovel angle of the current position of the blade.
In some embodiments, the current position comprises a position of a first edge angle and a position of a second edge angle of the blade, respectively.
According to a second aspect of the present disclosure, there is provided a leveling control device, comprising: an acquiring module configured to respectively acquire an elevation of a current position of a blade of a motor grader, an elevation of a target position, and a movement speed of the motor grader, wherein the target position is on the ground with a certain horizontal distance from the current position along a movement direction of the motor grader; a first determining module configured to determine a movement time of the blade from the current position to the target position according to the horizontal distance and the movement speed; a second determining module configured to determine a lifting speed of a lifting cylinder according to an elevation difference between the elevation of the target position and the elevation of the current position and the movement time; and a controlling module configured to control the lifting cylinder to adjust the blade to move from the current position to the target position according to the lifting speed.
According to a third aspect of the present disclosure, there is provided a leveling control device, comprising: a memory; and a processor coupled to the memory, the processor configured to perform the leveling control method according to any of the above embodiments based on instructions stored in the memory.
According to a fourth aspect of the present disclosure, there is provided a leveling control system comprising: the leveling control device according to any of the above embodiments.
In some embodiments, the leveling control system further comprises: a speed sensor arranged on any wheel of the motor grader and configured to measure a movement speed of the motor grader; and a Global Positioning System (GPS) fixedly arranged relative to a frame of the motor grader and configured to measure an elevation of the GPS; and a distance sensor fixedly arranged relative to a frame of the motor grader and configured to detect the ground to get a detection value.
In some embodiments, the GPS and the distance sensor are fixedly arranged relative to the frame of the motor grader by a first bracket and a second bracket, respectively.
In some embodiments, the GPS is located directly above the blade, and the distance sensor is spaced apart from the blade by a certain distance along the movement direction of the motor grader.
In some embodiments, the first bracket is perpendicular to a horizontal plane and the second bracket is parallel to the horizontal plane.
In some embodiments, the GPS comprises a first GPS and a second GPS, respectively located directly above the blade on both sides in a width direction of a body of the motor grader; and the distance sensor comprises a first distance sensor and a second distance sensor respectively spaced apart from the both sides along the movement direction of the motor grader by a certain distance, and the first distance sensor and the first GPS are both located on one sides of the both sides, and the second distance sensor and the second GPS are both located on the other side of the both sides.
According to a fifth aspect of the present disclosure, there is provided a motor grader comprising: the leveling control system according to any of the above embodiments.
According to a sixth aspect of the present disclosure, there is provided a non-transitory computer storable medium having stored thereon computer program instructions which, when executed by a processor, implement the leveling control method according to any of the above embodiments.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and together with the description, serve to explain the principles of the present disclosure.
The present disclosure may be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that: relative arrangements of parts and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present disclosure unless specifically stated otherwise.
Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description.
The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its applications, or uses.
Techniques, methods, and apparatus known to one of ordinary skill in the related art may not be discussed in detail but are intended to be part of the specification where appropriate.
In all examples shown and discussed herein, any particular value should be construed as exemplary only and not as restrictive. Thus, other examples of the exemplary embodiments may have different values.
It should be noted that: like reference numbers and letters refer to like items in the following drawings, and thus, once an item is defined in one drawing, it need not be discussed further in subsequent drawings.
In the related art, a hydraulic system of the motor grader has hysteresis, i.e., a certain time is required from the acquisition of the elevation of the blade to the actual adjustment of the blade to a preset elevation. However, the motor grader always operates at a certain speed, and the horizontal position of the blade has changed when the blade is adjusted to the preset elevation, resulting a poor leveling accuracy.
In view of this, the present disclosure provides a leveling control method, which improves leveling accuracy.
As shown in
In the present disclosure, the lifting speed of the blade is determined according to the elevation of the current position of the blade, the elevation of the target position and the movement speed of the motor grader, so that when the blade of the motor grader moves horizontally from the current position to the target position, the elevation of the blade changes from the elevation of the current position to the elevation of the target position, and the elevation of the blade keeps consistent with the actual elevation of the target position, which realizes the accurate control of the elevation of the blade, improves the leveling accuracy, and reduces an error between the adjusted elevation of the blade and an actual elevation of the ground position caused by the hysteresis of the hydraulic system.
In step S110, the elevation of the current position of the blade of the motor grader, the elevation of the target position, and the movement speed of the motor grader are acquired, respectively. The target position is on the ground with a certain horizontal distance from the current position along a movement direction of the motor grader. For example, in
The process of acquiring the elevation of the target position will be described in detail below with reference to
As shown in
In step S111, an elevation of GPS and a vertical distance between the GPS and the target position are acquired, respectively. For example, the GPS is a GPS receiver.
In some embodiments, the elevation of the GPS is a measurement ZGPS of the GPS. For example, the GPS 211 in
The step S111 of acquiring the vertical distance between the GPS and the target position, shown in
First, a vertical distance between the distance sensor and the target position is acquired. For example, in
For example, the distance sensor is an ultrasonic sensor or a lidar sensor.
In the case that the distance sensor is an ultrasonic sensor, the detection value is determined as the vertical distance between the distance sensor and the target position.
For example, in
In the case that the distance sensor is a lidar sensor, a product of the detection value and a cosine value of a laser emission angle of the lidar sensor is determined as the vertical distance between the distance sensor and the target position.
For example, in
Under the condition that the laser emission angle is within a certain range, a triangle formed by a connecting line between the lidar sensor and the detection position D, a connecting line between the lidar sensor and the target position B and a connecting line between the target position B and the detection position D can be approximately regarded as a right-angled triangle. According to the cosine law of the right-angled triangle, the vertical distance H1 between the distance sensor and the target position is S×cos θ. The lidar sensor is more accurate when being used in a secondary levelling scene.
Then, after the vertical distance between the distance sensor and the target position is acquired, the vertical distance between the GPS and the distance sensor is acquired.
In some embodiments, in
For example, in
For example, in
Finally, the vertical distance between the GPS and the target position is acquired according to the vertical distance between the distance sensor and the target position and the vertical distance between the GPS and the distance sensor.
For example, in
In step S112, the elevation of the target position is acquired according to the elevation of the GPS and the vertical distance between the GPS and the target position. For example, in
Returning to
The process of acquiring the elevation of the current position of the blade of the motor grader in the step S110, shown in
As shown in
In step S113, the elevation of the GPS is acquired. For example, the elevation ZGPS of the GPS 211 in
In step S114, the elevation of the current position of the blade of the motor grader is acquired according to the elevation of the GPS.
For example, in
First, the elevation of a projection point of the GPS on the ground is determined according to the distance between the GPS and the projection point of the GPS on the ground and the elevation of the GPS.
For example, in
When the vertical line segment between the upper edge and the lower edge of the blade 210 is perpendicular to the ground, a position of any edge angle of the lower edge of the blade is a projection point of the GPS 211 on the ground. For example, in
Next, the elevation of the current position of the blade is determined according to the elevation of the projection point of the GPS on the ground and a shovel angle of the current position of the blade.
For example, in
For example, in
In some embodiments, a radius of rotation of the blade 210 is the blade chord length L2. The blade chord length is a length of a vertical line segment between the upper edge and the lower edge of the blade. L2 can be obtained by measurement.
For example, the elevation ZA of the current position A of the blade 210 is zC+(L2−L2×cos α), i.e., ZA=ZGPS−(L1+L2)+(L2−L2×cos(2β)).
In some embodiments, there are a plurality of GPS. For example, in
In some embodiments, there comprise a plurality of distance sensors. For example, in
Specific positions of the two GPS and the two distance sensors on both sides of the body in the width direction may be set as required.
For example, in this case, the current position includes a position of a first edge angle and a position of a second edge angle of the blade. For example, in
Returning to
The step S110 of acquiring the movement speed of the motor grader is realized in the following manner for example.
In some embodiments, the movement speedy of the motor grader is acquired by a speed sensor arranged on any one wheel of the motor grader.
After the elevation of the current position of the blade of the motor grader, the elevation of the target position, and the movement speed of the motor grader are respectively acquired, the step S120 is continuously performed.
In the step S120, the movement time of the blade from the current position to the target position is determined according to the horizontal distance and the movement speed.
For example, in
For example, the movement time t of the blade 210 from the current position A to the target position B in
In the step S130, the lifting speed of the lifting cylinder is determined according to an elevation difference between the elevation of the target position and the elevation of the current position and the movement time.
For example, in
As can be learned from the physics kinematics, lifting cylinders 217a and 217b in
In
In the step S140, the lifting cylinder is controlled to adjust the blade to move from the current position to the target position according to the lifting speed.
For example, under the condition that the lifting speed is positive, the target position is higher than the current position, and the lifting cylinder is controlled to adjust the blade to rise from the current position according to the lifting speed so as to reach the target position. Under the condition that the lifting speed is negative, the target position is lower than the current position, and the lifting cylinder is controlled to adjust the blade to fall from the current position according to the lifting speed so as to reach the target position.
As shown in
The acquiring module 611 is configured to acquire an elevation of a current position of a blade of a motor grader, an elevation of a target position, and a movement speed of the motor grader, for example, to perform the step S110 shown in
The first determining module 612 is configured to determine a movement time of the blade from the current position to the target position according to the horizontal distance and the movement speed, for example, to perform the step S120 shown in
The second determining module 613 is configured to determine a lifting speed of a lifting cylinder according to an elevation difference between the elevation of the target position and the elevation of the current position and the movement time, for example, to perform the step S130 shown in
The controlling module 614 is configured to control the lifting cylinder to adjust the blade to move from the current position to the target position according to the lifting speed, for example, to perform the step S140 shown in
As shown in
As shown in
In some embodiments, the leveling control system 81 further comprises a speed sensor 811, a GPS 812, and a distance sensor 813.
The speed sensor 811 is arranged on any wheel of the motor grader. The speed sensor 811 is configured to measure a movement speed of the motor grader. For example, the speed sensor 811 is coupled to the leveling control controller 810 through a communication cable or communication protocol.
The GPS 812 is fixedly arranged relative to a frame of the motor grader. The GPS 812 is configured to measure an elevation of the GPS. The distance sensor 813 is fixedly arranged relative to the frame of the motor grader. The distance sensor 813 is configured to detect the ground to get a detection value. For example, the GPS 812 and the distance sensor 813 are coupled to the leveling control device 810 through a communication cable or a communication protocol.
In some embodiments, the leveling control system 81 further comprises a first lifting cylinder 814a and a second lifting cylinder 814b. The first and second lifting cylinders 814a and 814b are configured to adjust the elevation of the position of the first and second edge angles of the blade, respectively. For example, the first and second lifting cylinders 814a and 814b are left and right lifting cylinders of the motor grader, respectively.
In some embodiments, the leveling control system 81 further comprises a hydraulic multi-way valve 815. The leveling control device 810 controls the first and second lifting cylinders 814a and 814b through the hydraulic multi-way valve 815 to adjust the blade to move from the current position to the target position according to the calculated lifting speed.
For example, the present disclosure further proposes a motor grader. The motor grader comprises the leveling control system according to any of the embodiments of the present disclosure. For example, the leveling control system is similar in structure to the leveling control system 81 of the present disclosure.
As shown in
The memory 910 may include, for example, a system memory, a non-volatile storage media, and the like. The system memory stores, for example, an operating system, an application program, a Boot Loader, and other programs. The system memory may include volatile storage media, such as Random Access Memory (RAM) and/or cache memory. The non-volatile storage medium, for instance, stores instructions to perform respective embodiments of at least one of the leveling control methods. The non-volatile storage medium includes, but is not limited to, magnetic disk storage, optical storage, flash memory, and the like.
The processor 920 may be implemented as discrete hardware components, such as a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gates or transistors, or the like. Accordingly, each of the modules such as the judging module and the determining module may be implemented by a Central Processing Unit (CPU) executing instructions in the memory to perform the corresponding steps, or maybe implemented by a dedicated circuit to perform the corresponding steps.
The bus 900 may use any of a variety of bus structures. For example, the bus structures include, but are not limited to, Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, and Peripheral Component Interconnect (PCI) bus.
The computer system 90 can further include input/output interface 930, network interface 940, storage interface 950, and the like. The interfaces 930, 940, 950, as well as the memory 910 and the processor 920, may be coupled by the bus 900. The input/output interface 930 may provide a connection interface for input/output devices such as a display, a mouse, a keyboard, and the like. The network interface 940 provides a connection interface for a variety of networking devices. The storage interface 950 provides a connection interface for external storage devices such as a floppy disk, a USB disk, and an SD card.
Various aspects of the present disclosure are described herein with reference to flowcharts and/or block diagrams of the methods, devices and computer program products according to the embodiments of the present disclosure. It should be understood that each block of the flowcharts and/or block diagrams, and combinations of the blocks, can be implemented by computer-readable program instructions.
These computer-readable program instructions may be provided to a processor of a general purpose computer, a special purpose computer, or other programmable apparatus to produce a machine, such that the instructions, which when executed by the processor, create means for implementing the functions specified in one or more blocks of the flowchart and/or block diagram.
These computer readable program instructions may also be stored in a computer-readable memory that can direct a computer to function in a particular manner, so as to produce an article of manufacture, including instructions for implementing the functions specified in one or more blocks of the flowchart and/or block diagram.
The present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects.
By means of the leveling control method, device and system, the motor grader and the computer storable medium in the above embodiments, the leveling accuracy is improved.
Thus far, the leveling control method, device and system, the motor grader, the computer storable medium according to the present disclosure have been described in detail. Some details well known in the art have not been described in order to avoid obscuring the concepts of the present disclosure. Those skilled in the art would fully know how to implement the technical solutions disclosed herein, according to the above description.
Number | Date | Country | Kind |
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202010468500.3 | May 2020 | CN | national |